A heat engine receives 7000 j of heat and loses 3000 j in each cycle. what is the efficiency of this engine?

Question

asked Jan 6, 2019 116k views

1 Answer

Denis · Answer 1 · 2019-01-13T02:11:53+0000

Answer: 57.1 %

Step-by-step explanation:

The efficiency of the engine is given by:

$\eta=(Q_(used))/(Q_(in))$

where the numerator corresponds to the heat used by the engine, while the denominator corresponds to the heat in input to the engine.

In this problem, the heat in input is

Q_(in)=7000 J

while the heat used is

Q_(used)=7000 J-3000 J=4000 J

So, the efficiency is

$\eta=(4000 J)/(7000 J)=0.571=57.1\%$